Can you do your own tax return if you live outside the UK?

22/01/2026

Can you do your UK tax return yourself without the help of a Qualified Accountant?  The answer is yes - but with a bit of a twist if you are not resident in the UK.

If you are claiming non-residence and are doing a tax return just for your UK earnings (probably both of these are worth blog posts in future) then you must fill in what is called form SA109 each year which is declaring your residence status.  This is mandatory if you are doing a self assessment return.  Doing this has three choices:

- do the forms on paper and send to HMRC by post.  Not sure this is a good idea given how often things seem to get lost in the post between the UK and France - at least for me;

- buy software to fill in the tax return and the SA109 form together; or

- get someone to do the return for you - who will likely use professional software to do the SA109

Also, some of the questions in SA109 are maybe not that intuitive so check before answering. 

What you should not do is  (a) use HMRCs online software as it cannot handle SA109 (b) attach a scanned SA109 to the HMRC online tax return [HMRC guidance notes say you must not do this] or (c) not bother with it and hope it is not a problem.  

The implications of getting it wrong could be expensive.  Do do some googling on this and do not just trust me but it goes from a minimum of the return technically being invalid so you could get late filing penalties up to HMRC trying to tax you on your whole worldwide income with penalties on top.  So potentially expensive or time consuming.  

Yes you can fix it while the filing window is open.  Go back and fix your previous year return through a resubmission and it closes the immediate issue.